PaperPanorama
FAQ

Nuclear Theory·nucl-th

Friday·June 7, 2019

13 papers—5 primary·8 cross-listed

All13Primary5Cross-lists8
  1. 01

    Near-threshold meson production in reactions

    E.Ya.Paryev🇷🇺

    We study the inclusive near-threshold production of mesons in meson-nucleus reactions on the basis of the first-collision model relying on the nuclear spectral function and including incoherent processes of production in meson--proton collisions. The model accounts for the absorption of initial and final mesons, the binding of intranuclear protons and their Fermi motion, as well as the effect of the scalar --nucleus potential (or the in-medium shift of the meson mass) on these processes. We calculate the differential and total cross sections for production off carbon and tungsten nuclei at laboratory angles of 0--10 and 10--45 by mesons with momentum of 1.7 GeV/c, which is close to the threshold momentum for creation on a free target proton at rest. We show that the calculated production cross sections are larger than those, studied earlier in the photoproduction reactions, by about two orders of magnitude. We also demonstrate that the high absolute values of the present differential and total production cross sections in the momentum ranges of 0.2--0.3 GeV/c and 0.1--0.6 GeV/c, respectively, possess a high sensitivity to changes in the in-medium shift of the mass. This offers the possibility of evaluating the above shift at these momenta from the respective data, which could be taken in future experiments at the GSI pion beam facility or at J-PARC.

    nucl-thnucl-exNPA(2019)·2 citations
  2. 02

    Absence of hindrance in microscopic C+C fusion study

    K. Godbey · C. Simenel · A. S. Umar

    Background: Studies of low-energy fusion of light nuclei are important in astrophysical modeling, with small variations in reaction rates having a large impact on nucleosynthesis yields. Due to the lack of experimental data at astrophysical energies, extrapolation and microscopic methods are needed to model fusion probabilities. Purpose: To investigate deep sub-barrier C+C fusion cross sections and establish trends for the factor. Method: Microscopic methods based on static Hartree-Fock (HF) and time-dependent Hartree-Fock (TDHF) mean-field theory are used to obtain C+C ion-ion fusion potentials. Fusion cross sections and astrophysical factors are then calculated using the incoming wave boundary condition (IWBC) method. Results: Both density-constrained frozen Hartree-Fock (DCFHF) and density-constrained TDHF (DC-TDHF) predict a rising factor at low energies, with DC-TDHF predicting a slight damping in the deep sub-barrier region (~MeV). Comparison between DC-TDHF calculations and maximum experimental cross-sections in the resonance peaks are good. However the discrepancy in experimental low energy results inhibits interpretation of the trend. Conclusions: Using the fully microscopic DCFHF and DC-TDHF methods, no factor maximum is observed in the C+C fusion reaction. In addition, no extreme sub-barrier hindrance is predicted at low energies. The development of a microscopic theory of fusion including resonance effects, as well as further experiments at lower energies must be done before the deep sub-barrier behavior of the reaction can be established.

    nucl-thPRC(2019)·33 citations
  3. 03

    Light (anti)nuclei production in Cu+Cu collisions at GeV

    Liu Feng-Xian🇨🇳 · Chen Gang🇨🇳 · She Zhi-Lei🇨🇳 · Zhou Dai-Mei🇨🇳 · Xie Yi-Long🇨🇳

    The production of light (anti)nuclei have been investigated using the dynamically constrained phase-space coalescence model based on the final-state hadrons generated by the PACIAE model in Cu+Cu collisions at GeV with and GeV/c. The results show that there is a strong centrality dependence of yields of , , , , , and , i.e., their yields decrease rapidly with the increase of centrality, and the greater the mass is, the greater the dependence shows; whereas their ratio of antinucleus to nucleus and coalescence parameter remain constant as the centrality increases. In addition, the yields of (anti)nuclei are strongly dependent on the mass of the (anti)nuclei, indicating that the (anti)nuclei produced have mass scaling properties in high-energy heavy-ion collisions. Our results are consistent with the STAR experimental data.

    nucl-thnucl-exEPJA(2019)·10 citations
  4. 04

    Finite size effects on cumulants of the critical mode

    Moussa Agah Nouhou (SUBATECH, Nantes)🇫🇷 · Marcus Bluhm (Wroclaw U. & SUBATECH, Nantes)🇵🇱 · Anna Borer🇫🇷 · Marlene Nahrgang🇫🇷 · Taklit Sami🇫🇷 · Nathan Touroux (SUBATECH, Nantes)🇫🇷

    In this work we study the temperature dependence of the equilibrium variance of critical fluctuations near the QCD critical point. In particular, we take the finite size of the fireball created in heavy-ion collisions into account and systematically obtain corrections to the leading-order result. We find that not only is the variance globally reduced in a finite size system, but for certain combinations of parameters a two-peak structure can develop for temperatures near the critical point.

    nucl-thhep-phPoS(2019)·8 citations
  5. 05

    New method of analytic continuation of elastic-scattering data to the negative-energy region and asymptotic normalization coefficients for O and C

    L. D. Blokhintsev · A. S. Kadyrov · A. M. Mukhamedzhanov · D. A. Savin

    A new method is proposed for extrapolation of elastic-scattering data to the negative-energy region for a short-range interaction. The method is based on the analytic approximation of the modulus-squared of the partial-wave scattering amplitude. It is shown that the proposed method has an advantage over the traditional one based on continuation of the effective-range function. The new method has been applied to determine the asymptotic normalization coefficients for the O and C nuclei in the O and C channels, respectively.

    nucl-thPRC(2019)·8 citations

Affiliations

first authorsco-authorsvia INSPIRE